SELECTIVE THERMAL ETCHING METHODS OF METAL OR METAL-CONTAINING MATERIALS FOR SEMICONDUCTOR MANUFACTURING

Abstract

In described embodiments, methods for selective etching (thermal etching) of metals, especially molybdenum- and tungsten-containing materials, and titanium nitride, using thionyl chloride (SOCl.sub.2) as an etching gas at low temperatures and low pressure without a need of plasma, for device manufacturing processes and for process chamber cleanings are disclosed. Methods for cleaning reaction product deposits from interior surface of a reactor chamber or from a substrate within said reaction chamber using thionyl chloride (SOCl.sub.2) at low temperatures and low pressure without a need of plasma are also disclosed. An additional co-reactant such as hydrogen may be used in combination with thionyl chloride. The processes are carried out in temperature ranging from approximately 150° C. to approximately 600° C., pressure under<100 Torr without the need of a plasma-activation.

Claims

1. A method for selective etching a substrate, the method comprising: introducing a vapor of thionyl chloride (SOCl.sub.2, CAS number: 7719-09-7) into a reaction chamber containing the substrate that has at least one metal or metal-containing films deposited thereon; and allowing an etching reaction to proceed between SOCl.sub.2 and the at least one metal or metal-containing films to selectively etch the at least one metal or metal-containing films, thereby etching the substrate.

2. The method of claim 1, further comprising: maintaining a temperature of the reaction chamber from approximately 150° C. to approximately 600° C.

3. The method of claim 1, further comprising: maintaining a pressure in the reaction chamber less than 100 Torr.

4. The method of claim 1, further comprising: introducing a co-reactant into the reaction chamber in a continuous, pulsing or cyclic mode.

5. The method of claim 4, wherein the co-reactant is H.sub.2, F.sub.2, NO, O.sub.2, COS, CO.sub.2, CO, NO.sub.2, SO.sub.2O.sub.3, Cl.sub.2, HF, HBr or HCl.

6. The method of claim 1, wherein the vapor of thionyl chloride includes an inert gas.

7. The method of claim 6, wherein the inert gas is selected from N.sub.2, Ar, Kr, Ne, He, Xe, or combinations thereof.

8. The method of claim 1, wherein SOCl.sub.2 is not activated by a plasma.

9. The method of claim 1, wherein SOCl.sub.2 is activated by a plasma.

10. The method of claim 1, wherein SOCl.sub.2 is activated by heat.

11. The method of claim 1, wherein the substrate is a pattern containing silicon-containing and metal or metal-containing layers, so that the at least one metal or metal-containing films is selectively etched.

12. The method of claim 1, wherein the at least one metal or metal-containing film contains Mo-containing materials, W-containing materials, Ti-containing materials, Ta-containing materials, Nb-containing, Ru-containing, Rh-containing materials, Co-containing materials, Ni-containing materials, Fe-containing materials, Hf-containing materials, Zr-containing materials, V-containing materials or combinations thereof.

13. A method for cleaning reaction product deposits from interior surface of a reactor chamber or from a substrate within said reaction chamber, the method comprising: exposing the reaction product deposits to a vapor, wherein the vapor comprises a vapor of thionyl chloride (SOCl.sub.2, CAS number: 7719-09-7); allowing an etching reaction to proceed between SOCl.sub.2 and the reaction product deposits to convert the reaction product deposits into volatile products; and evacuating the remaining SOCl.sub.2 together with substantially all volatile products of the etching reaction.

14. The method of claim 13, further comprising: maintaining a temperature of the reactor chamber from approximately 150° C. to approximately 600° C. while exposing the reaction product deposits to the vapor.

15. The method of claim 13, further comprising: maintaining a pressure in the reaction chamber less than 100 Torr.

16. The method of claim 13, further comprising: introducing a co-reactant into the reaction chamber in a continuous, pulsing or cyclic mode.

17. The method of claim 16, wherein the co-reactant is H.sub.2, F.sub.2, NO, O.sub.2, COS, CO.sub.2, CO, NO.sub.2, SO.sub.2O.sub.3, Cl.sub.2, HF, HBr or HCl.

18. The method of claim 13, wherein the reaction product deposits contains metal and metal-containing particles or films.

19. The method of claim 18, wherein the metal or metal-containing particles or films contain Mo-containing materials, W-containing materials, Ti-containing materials, Ta-containing materials, Nb-containing, Ru-containing, Rh-containing materials, Co-containing materials, Ni-containing materials, Fe-containing materials, Hf-containing materials, Zr-containing materials, V-containing materials or combinations thereof.

20. The method of claim 13, wherein the vapor of thionyl chloride includes an inert gas selected from N.sub.2, Ar, Kr, Ne, He, Xe, or combinations thereof.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0073] For a further understanding of the nature and objects of the present invention, reference should be made to the following detailed description, taken in conjunction with the accompanying drawings, in which like elements are given the same or analogous reference numbers and wherein:

[0074] FIG. 1a is a schematic representation of an exemplary cross-sectional side view of an exemplary work piece to be etched;

[0075] FIG. 1b is a schematic representation of an exemplary cross-sectional side view of an isotropic opening formed in the substrate shown in FIG. 1a;

[0076] FIG. 2a is a schematic representation of an exemplary cross-sectional side view of gate dielectric and metal deposited in a 3D NAND opening;

[0077] FIG. 2b is a schematic representation of an exemplary cross-sectional side view of vertically etched metal material from the 3D NAND opening shown in FIG. 2a;

[0078] FIG. 3 is a set of SEM images over various times for Mo etching using SOCl.sub.2 at 250° C.;

[0079] FIG. 4 is a set of SEM images over various times for Mo etching using SOCl.sub.2 at 300° C.;

[0080] FIG. 5 is XPS results of Mo film on SiO.sub.2 before etching;

[0081] FIG. 6 is a set of XPS results of Mo films at 300° C.;

[0082] FIG. 7 is a set of XPS results of Mo films at 350° C.:

[0083] FIG. 8 is a set of XPS results of Mo films at 400° C.;

[0084] FIG. 9 is a set of XPS results of HfO.sub.2 film on SiO.sub.2 before etching;

[0085] FIG. 10 is a set of XPS results of HfO.sub.2 film at 400° C. with 5% of SOCl.sub.2;

[0086] FIG. 11 is a set of XPS results of ZrO.sub.2 film on SiO.sub.2 before etching;

[0087] FIG. 12 is a set of XPS results of ZrO.sub.2 film at 400° C. with 5% of SOCl.sub.2;

[0088] FIG. 13 is a set of etch rates of SOCl.sub.2 over temperature (T-SiO.sub.2 (thermal SiO.sub.2) TiO.sub.2, TiN, Mo and InO.sub.x);

[0089] FIG. 14 is a set of etch rates of SOCl.sub.2 over temperature study (Poly-Si, SiN, T-SiO.sub.2 Ru and W);

[0090] FIG. 15 is a set of etch rate of SOCl.sub.2 over concentrations of SOCl.sub.2 (Poly-Si, SiN and T-SiO.sub.2);

[0091] FIG. 16 is a set of etch rate of SOCl.sub.2 over concentrations of SOCl.sub.2 (SiN, TiO.sub.2 and TiN);

[0092] FIG. 17 is a set of etch rates of SOCl.sub.2 over concentration effect (SiN, T-SiO.sub.2, Mo and InO.sub.x);

[0093] FIG. 18 is a set of selectivity results of SOCl.sub.2 etching Poly-Si;

[0094] FIG. 19 is a set of selectivity results of SOCl.sub.2 etching to SiN;

[0095] FIG. 20a is an image of the quart tube chamber before cleaning;

[0096] FIG. 20b is an image of the quart tube chamber after cleaning;

[0097] FIG. 21a is an image of the hot area of the quart tube chamber before cleaning; and

[0098] FIG. 21b is an image of the hot area of the quart tube chamber after cleaning.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0099] Disclosed are methods for selective dry etching of metals or metal-containing films, especially molybdenum- and tungsten-containing materials, and titanium nitride, using thionyl chloride (SOCl.sub.2) (CAS number: 7719-09-7) with or without hydrogen as an etching gas at low temperatures and low pressure without a need of plasma, for device manufacturing processes and for process chamber cleanings. The metal or metal-containing film contains Mo-containing materials, W-containing materials, Ti-containing materials, Ta-containing materials, Nb-containing, Ru-containing, Rh-containing materials, Co-containing materials, Ni-containing materials, Fe-containing materials, Hf-containing materials, Zr-containing materials, V-containing materials or combinations thereof. The disclosed also include methods for cleaning reaction product deposits from interior surface of a reactor chamber or from a substrate within said reaction chamber using thionyl chloride (SOCl.sub.2) at low temperatures and low pressure without a need of plasma. The product deposits include metal and metal-containing particles or films. A co-reactant such as hydrogen may be used in combination with thionyl chloride. The co-reactant is selected from H.sub.2, F.sub.2, NO, O.sub.2, COS, CO.sub.2, CO, NO.sub.2, SO.sub.2, O.sub.3, Cl.sub.2, HF, HBr or HCl. The disclosed methods operate at low temperatures ranging from approximately 150° C. to approximately 600° C., low pressures under<100 Torr without the need of a plasma-activation.

[0100] Furthermore, selective etching of these materials versus commonly used substrate materials, such as silicon oxide or aluminum oxide may be achieved with the disclosed methods.

[0101] The disclosed methods may be used to thermally etch silicon-containing layers on a substrate. The disclosed etching method may be useful in the manufacture of semiconductor devices such as NAND or 3D NAND gates or Flash or DRAM memory. The disclosed etching methods may be used in other areas of applications, such as different front end of the line (FEOL) and back end of the line (BEOL) etch applications. Additionally, the disclosed methods may also be used for etching Si in 3D TSV (Through Silicon Via) etch applications for interconnecting memory substrates on logic substrates.

[0102] The disclosed methods are based on a halogenating reagent, SOCl.sub.2, which is commonly used as an inexpensive and readily available halogenating agent in synthetic chemistry. The disclosed methods utilize the properties of SOCl.sub.2 to convert metal-containing materials into volatile chloride-containing metal compounds.

[0103] Exemplary films to be etched may include Mo-containing films, Ti-containing films, Ta-containing films, W-containing films, Nb-containing, Ru-containing, Rh-containing films, Co-containing films, Ni-containing films, Fe-containing films, Hf-containing films, Zr-containing films, V-containing films or combination thereof. Exemplary films to be etched may alternatively include metal films, such as Mo, oxides thereof, nitrides thereof, or combinations thereof. For example, in the case of the metal-containing materials being molybdenum oxide, one possible reaction is SOCl.sub.2 may react with molybdenum oxide to form volatile chloride-containing molybdenum compounds and volatile sulfur compounds.

[0104] The boiling point of SOCl.sub.2 is around 79° C. SOCl.sub.2 may decompose above around 80° C. to form a mixture of SO.sub.2, Cl.sub.2, S.sub.2Cl.sub.2 and related etch-active and inactive species. In addition, the etching performance of SOCl.sub.2 may be improved by adding hydrogen as an additional reactant to the above mixture, resulting in a two component etching process. Besides, the etching with the halogenating reagent, SOCl.sub.2, and subsequent treatment with H.sub.2 may be used to eliminate metal and metal oxide residual layers attached to the wall of a reaction chamber in a deposition tool. In the disclosed methods, etching temperature is in a range of approximately 150° C. to approximately 600° C., in which SOCl.sub.2 is a vapor and may decompose to the mixture of SO.sub.2, Cl.sub.2, S.sub.2Cl.sub.2 and the related etch-active and inactive species. The disclosed methods do not need plasma-activated SOCl.sub.2 and H.sub.2.

[0105] The disclosed methods comprise the usage of one component SOCl.sub.2 alone or a mixture of two components (e.g., SOCl.sub.2 and H.sub.2) to achieve selective and non-selective thermal etching with applications in logic and memory patterning processes. The mixture of the two components include SOCl.sub.2 and a co-reactant. The co-reactant is selected from H.sub.2, F.sub.2, NO, O.sub.2, COS, CO.sub.2, CO, NO.sub.2, SO.sub.2O.sub.3, Cl.sub.2, HF, HBr or HCl. The co-reactant may be introduced into a reaction chamber in a continuous, pulsing or cyclic mode. SOCl.sub.2 or the mixture of two components (e.g., SOCl.sub.2 and H.sub.2) may provide high etch selectivity to metal or metal-containing films versus mask layers, photoresist, etch stop layers, device channel materials and silicon-containing films, in applications such as DRAM and 3D NAND. SOCl.sub.2 or the mixture of two components may provide infinite selectivity for wide process conditions of etching. Herein the selectivity refers to the etching rate ratio of two different etched layers.

[0106] SOCl.sub.2 is provided at greater than 95% v/v purity, preferably at greater than 99.99% v/v purity, and more preferably at greater than 99.999% v/v purity. SOCl.sub.2 contains less than 5% by volume trace gas impurities, with less than 150 ppm by volume of impurity gases, such as SO.sub.2Cl.sub.2, S.sub.2Cl.sub.2, SCl.sub.2, SO.sub.2, Cl.sub.2, acid impurities contained in said trace gaseous impurities. Preferably, the water content in SOCl.sub.2 and or the mixture of SOCl.sub.2 and H.sub.2 is less than 20 ppm by weight.

[0107] SOCl.sub.2 or the mixture of two components is suitable for dry etching semiconductor structures, such as, channel holes, gate trenches, staircase contacts, slits, capacitor holes, contact holes, etc., in metal/metal-containing films without a need of plasma activation. SOCl.sub.2 or the mixture of two components may etch desired metal or metal-containing layers with less damage to underlayers, such as p-Si or crystalline Si channel structures during etching than other etching processes, such as plasma etching.

[0108] In one embodiment, a substrate having a material (e.g., a metal or metal-containing layer) to be etched, such as a semiconductor workpiece, is loaded into a reaction space or process chamber that is heated to a predetermined temperature. The semiconductor workpiece may be a workpiece for producing 3D NAND or DRAM structures, etc., in semiconductor applications. The reaction chamber may contain one or more than one substrate. For example, the reaction chamber may contain from 1 to 200 substrate wafers having from 25.4 mm to 450 mm diameters. The substrates may be any suitable substrates used in semiconductor, photovoltaic, flat panel or LCD-TFT device manufacturing. Examples of suitable substrates include wafers, such as silicon, silica, glass, or GaAs wafers. The wafer will have multiple films or layers deposited on it from previous manufacturing steps, including metal or metal-containing films or layers. The layers may or may not be patterned. Examples of suitable layers include without limitation molybdenum- and tungsten-containing layer materials, and titanium nitride layer material, mask layer materials such as amorphous carbon with or without dopants, antireflective coatings, photoresist materials, tungsten, titanium nitride, tantalum nitride or combinations thereof, etch stop layer or landing layer materials such as silicon nitride, polysilicon, crystalline silicon, silicon carbide, SiCN or combinations thereof, etc. Throughout the specification and claims, the wafer and any associated layers thereon are referred to as substrates.

[0109] The material to be etched in the substrate or the material to be etched in the semiconductor workpiece is selectively etched by SOCl.sub.2 or the mixture of two components. FIG. 1a is an exemplary cross-sectional side view of an exemplary workpiece to be etched. The exemplary workpiece includes a metal or metal-containing films 104 deposited on top of a wafer such as a silicon wafer 102 and a patterned mask layer 106 deposited on top of a metal or metal-containing films 104. The patterned mask layer 106 (e.g., a-C mask layer) other layers such as antireflective coating and photoresist layer (not shown) which may be deposited on the metal or metal-containing films 104 are less reactive with SOCl.sub.2 or the mixture of two components. Thus, SOCl.sub.2 or the mixture of two components selectively reacts with the metal or metal-containing material to form volatile by-products thereby producing a desired isotropic opening 108 in the metal or metal-containing films 104, as shown in FIG. 1b. FIG. 1b is an exemplary cross-sectional side view of an isotropic opening formed in the substrate shown in FIG. 1a.

[0110] Alternatively, the material to be etched by SOCl.sub.2 or the mixture of two components is in a 3D NAND structure such as in a gate recess process, as shown in FIG. 2a. An aperture 206 in the 3D NAND structure is deposited with a thin oxide/charge-trap layer 208 and a metal layer 210. The 3D NAND structure includes alternating layers 202 of a SiO.sub.2 layer 204 and the metal layer 210. A silicon wafer in the bottom of the 3D NAND and a patterned hardmask layer on the top of the 3D NAND are not shown. The SiO.sub.2 layer 204 isolates charge-trap transistors. Channels 212 is a poly-Si channel. The thin oxide/charge-trap layer 208 may be a stack of SiO.sub.2/SiN/TaN, SiO.sub.2/SiN/HfO.sub.2, SiO.sub.2/SiN/ZrO.sub.2, etc. The metal layer 210 may be a layer of W, Mo, Ru, etc. FIG. 2b is an exemplary cross-sectional side view of a vertically etched 3D NAND structure of FIG. 2a using SOCl.sub.2 or the mixture of the two components. The metal layer 210 is vertically etched by SOCl.sub.2 or the mixture of the two components without plasma activation, forming an aperture 214 that is an enlarged aperture 206 in FIG. 2a and separates gate nodes in the gate recess process. One of ordinary skill in the art will recognize that the stack of layers in the 3D NAND, the apertures and geometry of layers depicted in FIG. 2a and FIG. 2b are provided for exemplary purposes only.

[0111] The disclosed methods also include cleaning a deposition/reaction chamber or removing residual layers deposited on the wall of the deposition chamber by etching residual deposits as target materials using pure SOCl.sub.2 or a mixture of SOCl.sub.2 with H.sub.2. The residual deposits are reaction product deposits from the interior surface of a reactor chamber or from a substrate within the reaction chamber. SOCl.sub.2 or the mixture of two components reacts with the residual deposits to form volatile products, such as volatile chloride-containing metal compounds. The residual deposits may contain metal or metal-containing particles and/or films. The method for cleaning reaction product deposits from interior surface of a reactor chamber or from a substrate within said reaction chamber comprises exposing the reaction product deposits to a vapor, wherein the vapor comprises a vapor of an etchant SOCl.sub.2 or the mixture of two components, allowing an etching reaction to proceed between SOCl.sub.2 or the mixture of two components and the reaction product deposits to convert the reaction product deposits into volatile products, and evacuating the remaining SOCl.sub.2 or the mixture of two components together with substantially all products of the etching reaction.

[0112] In the disclosed methods, the vapor of SOCl.sub.2 or the mixture of two components is introduced into the reaction chamber containing the substrate and metal or metal-containing films deposited thereon. The vapor may be introduced to the chamber at a flow rate ranging from approximately 0.1 sccm to approximately 2 sim. One of ordinary skills in the art will recognize that the flow rate may vary from tool to tool.

[0113] SOCl.sub.2 may be supplied either in neat form or in a blend with an inert gas, such as N.sub.2, Ar, Kr, Ne, He, Xe, etc., preferably N.sub.2 or Ar, or hydrogen. Other exemplary gases with which SOCl.sub.2 may be mixed include additional gases, such as F.sub.2, NO, O.sub.2, COS, CO.sub.2, CO, NO.sub.2, SO.sub.2O.sub.3, Cl.sub.2, HF, HBr, HCl. SOCl.sub.2 may be present in varying concentrations in the blend. The neat or blended SOCl.sub.2 may be fed to a vaporizer where it is vaporized before it is introduced into the reactor.

[0114] Alternatively, the neat or blended SOCl.sub.2 may be vaporized by passing a carrier gas into a container containing SOCl.sub.2 or by bubbling the carrier gas into SOCl.sub.2. The carrier gas may include, but is not limited to, Ar, He, N.sub.2, Kr, Xe, Ne and mixtures thereof. Bubbling with a carrier gas may also remove any dissolved oxygen present in the neat or blended SOCl.sub.2 solution. The carrier gas and SOCl.sub.2 are then introduced into the reactor as a vapor.

[0115] SOCl.sub.2 is liquid in ambient conditions. If necessary, a container containing SOCl.sub.2 may be heated to a temperature that permits SOCl.sub.2 to be a vapor for delivery into an etching tool. The container may be maintained at temperatures in the range of, for example, approximately 0° C. to approximately 80° C., preferably from approximately 0° C. to approximately 30° C., to permit SOCl.sub.2 supply. Those skilled in the art recognize that the temperature of the container may be adjusted in a known manner to control the amount of SOCl.sub.2 vaporized.

[0116] Additionally, SOCl.sub.2 is delivered in purity ranging from 95% to 99.999% by volume and may be purified with known standard purification techniques for removal of SO.sub.2Cl.sub.2, S.sub.2Cl.sub.2, SCl.sub.2, SO.sub.2, Cl.sub.2, and acid impurities.

[0117] A quadrupole mass spectrometer (QMS), FTIR may measure the activated etching gas from the chamber exhaust to determine the types and numbers of species produced. If necessary, the flow rate of the etching gas and/or the inert gas may be adjusted to increase or decrease the number of radical species produced.

[0118] SOCl.sub.2 may be mixed with hydrogen gas either prior to introduction into the reaction chamber or inside the reaction chamber. Preferably, the SOCl.sub.2 and H.sub.2 gases may be mixed prior to introduction to the chamber in order to provide a uniform concentration of the entering gas.

[0119] In another alternative, the vapor of SOCl.sub.2 may be introduced into the chamber independently of H.sub.2, such as when two gases react or are easier to deliver independently.

[0120] The metal or metal-containing films and SOCl.sub.2 react to form volatile by-products that are removed from the reaction chamber. The a-C mask, antireflective coating, and photoresist layer which may deposited on the metal or metal-containing films, or underlayers, such as etch stop layers, device channel materials and silicon-containing films, are less reactive with SOCl.sub.2 or the mixture of two components. Thus, the etching gas SOCl.sub.2 or the mixture of two components selectively reacts with the metal or metal-containing materials to form volatile by-products that is purged or evacuated subsequently.

[0121] The temperature and the pressure within the reaction chamber are held at conditions suitable for the metal or metal-containing films to react with the vapor SOCl.sub.2. For instance, the pressure in the chamber may be held less than 100 Torr, preferably, less than 15 Torr (approximately 20 mbar), more preferably between 0.1 Torr and 15 Torr, even more preferably between 1 Torr and 10 Torr, as required by etching parameters. Likewise, the substrate temperature in the chamber may range between about approximately 150° C. to approximately 600° C., preferably between approximately 200° C. to approximately 400° C., more preferably between approximately 250° C. to approximately 300° C., depending on process requirements.

[0122] The reaction between the metal or metal-containing films and SOCl.sub.2 or the mixture of two components results in isotropic removal of the metal or metal-containing films from the substrate.

EXAMPLES

[0123] The following non-limiting examples are provided to further illustrate embodiments of the invention. However, the examples are not intended to be all inclusive and are not intended to limit the scope of the inventions described herein.

Example 1: Etching of Mo Films

[0124] Etching of Mo thin films has been performed using SOCl.sub.2 (chamber temperature (T.sub.cham), chamber pressure (P.sub.cham), canister temperature (T.sub.can), canister Pressure (P.sub.can), flow rate (FR), partial pressure (PP), residence time, etc. listed for each experiment) as the etchant gas at temperatures between 250 and 400° C. at 10 Torr. Although the samples contained a 5 nm layer of native Mo oxide on top of pure Mo film, etching has been achieved applying SOCl.sub.2 at temperatures above 250° C.

[0125] Table 1 is Mo film etching by SOCl.sub.2 at 250° C. and 300° C., respectively, which includes the process conditions used to etch Mo film by SOCl.sub.2 at 250° C. and 300° C., respectively. Table 2 is an Ellipsometry summary for Mo etching using SOCl.sub.2 at 250° C. versus various times with SEM images shown in FIG. 3. Table 3 is an Ellipsometry summary for Mo etching using SOCl.sub.2 at 300° C. versus various times with SEM images shown in FIG. 4.

[0126] Etch rates have been estimated to be 0.144 nm/min based on scanning electron microscopy (SEM) results and 0.122 nm/min based on Ellipsometry results at 250° C. and 0.806 nm/min based on SEM results and 0.862 nm/min based on Ellipsometry results at 300° C. While no sign of etching was observed at 200° C., Mo was completely removed at 400° C. within 5 min (etch rate>6.2 nm/min). This shows that SOCl.sub.2 is an efficient etchant towards Mo at temperatures above 200° C.

TABLE-US-00001 TABLE 1 Total SOCl.sub.2 Resi reaction T.sub.cham P.sub.cham Ar FR T.sub.can P.sub.can FR PP time time (° C.) (Torr) (sccm) (° C.) (Torr) (sccm) (Torr) (sec) (min) 250 10 100 1 300 2.67 57 2.56 10 ~ 60 300 10 100 1 300 2.67 57 2.56 10 ~ 60

TABLE-US-00002 TABLE 2 Etching temperature (° C.) Time (min) Etched MoThickness (nm) 250 10 0.6 250 30 3.6 250 60 8.4 Initial Mo film 34.2 nm; Etch rate = 0.13 nm/min

TABLE-US-00003 TABLE 3 Etching temperature (° C.) Time (min) Etched Mo Thickness (nm) 300 10 9.2 300 30 24.4 300 60 34.2 Initial Mo film 34.2 nm; Etch rate = 0.82 nm/min

Example 2: Mo Film Depth Profile Etching with SOCl.SUB.2

[0127] FIG. 5 is XPS results of Mo film on SiO.sub.2 before etching. FIG. 6 to FIG. 8 are XPS results of Mo films at 300° C., 350° C. and 400° C., respectively.

Example 3: HfO.SUB.2 .Depth Profile Etching with SOCl.SUB.2

[0128] FIG. 9 is XPS results of HfO.sub.2 film on SiO.sub.2 before etching. FIG. 10 is XPS results of HfO.sub.2 film at 400° C. with 5% of SOCl.sub.2.

Example 4: ZrO.SUB.2 .Depth Profile Etching with SOCl.SUB.2

[0129] FIG. 11 is XPS results of ZrO.sub.2 film on SiO.sub.2 before etching. FIG. 12 is XPS results of ZrO.sub.2 film at 400° C. with 5% of SOCl.sub.2.

Example 5: SOCl.SUB.2 .Etch Rate

[0130] Examples 5 to 7 were carried out at the following conditions listed in Table 4.

TABLE-US-00004 TABLE 4 Process gas (bubbling) SOCl.sub.2 Concentration 0.6 to 5% Carrier/dilution gas flow rate N.sub.2 500 sccm Total flow rate 500 sccm Etching time 15 to 1800 seconds Pressure 5 to 50 Torr Temperature 300 to 450° C. Sample size 1 cm × 1 cm

[0131] FIG. 13 is etch rates of SOCl.sub.2 over temperature (T-SiO.sub.2 (thermal SiO.sub.2) TiO.sub.2 TiN, Mo and InO.sub.x). The etch rates of TiO.sub.2, TiN and Mo are increasing as the temperature increases. The etch rates of T-SiO.sub.2 and InO.sub.x (x>0) remain almost zero with the temperature increasing.

[0132] FIG. 14 is etch rates of SOCl.sub.2 over temperature study (Poly-Si, SiN, T-SiO.sub.2 Ru and W). The etch rate of Poly-Si reaches to 1.2 nm/min at 400° C.

[0133] FIG. 15 is etch rate Of SOCl.sub.2 over concentrations Of SOCl.sub.2 (Poly-Si, SiN and T-SiO.sub.2). The etch rate of Poly-Si is increasing as the concentration increases. The etch rate of Poly-Si reaches to 0.8 nm/min with 5.0% of SOCl.sub.2 concentration. T-SiO.sub.2 and plasma enhanced SiN (PE-SiN) were not etched.

[0134] FIG. 16 is etch rate of SOCl.sub.2 over concentrations of SOCl.sub.2 (SiN, TiO.sub.2 and TiN). The etch rates of TiO.sub.2 and TiN are increasing as the concentration increases, respectively. However, the etch rate of TiO.sub.2 has a turning point at 3.0% of SOCl.sub.2 concentration. The etch rate of TiN has no turning points. T-SiO.sub.2 was not etched.

[0135] FIG. 17 is etch rate Of SOCl.sub.2 over concentration effect (SiN, T-SiO.sub.2, Mo and InO.sub.x). The etch rate of Mo maintained at 2.0 nm/min with the concentrations from 1.0% to about 3.5%, and then reduced to 1.5 nm/min with around 4.5% of SOCl.sub.2 concentration. The etch rate of InO.sub.x has a turning point at around 3.5% of SOCl.sub.2 concentration, that is, increased below around 3.5% and then reduced above around 3.5% of SOCl.sub.2 concentration. The etchrate of T-SiO.sub.2 almost remained close to 0 over the concentration range of 0 to 5.0%. the etch rate of PE-SiN was below around 0.25 nm/min, reduced below around 3.5% of SOCl.sub.2 concentration and then increased above around 3.5% of SOCl.sub.2 concentration.

Example 6: SOCl.SUB.2 .Selectivity

[0136] FIG. 18 is selectivity results of SOCl.sub.2 etching Poly-Si. The etching of metal containing materials by SOCl.sub.2 shows high selectivity to PolySi, because the etch rate of PolySi with 0.6% SOCl.sub.2 is very low in the temperature range we investigated. The selectivity increases with increasing temperature. FIG. 19 is selectivity results of SOCl.sub.2 etching to SiN. The etch rate of SiN in the temperature range is close to 0, therefore the selectivity of Mo, TiO.sub.2, TiN and InO.sub.x to SiN were significantly high.

Example 7: Etching Rate of Highk

[0137] HfO.sub.2 and ZrO.sub.2 are high-k materials which have higher relative permittivity than SiO.sub.2. These two materials are promising insulators to replace SiO.sub.2 for future miniaturization, but there are not many technologies that can control the amount of etching with particular precision. SOCl.sub.2 can etch HfO.sub.2 and ZrO.sub.2 at sub-nm/min order at 400° C. (Table 5). This also shows the possibility of controlling the amount of etching by the SOCl.sub.2 cycling process. FIG. 9 to FIG. 12 show the XPS results of HfO.sub.2 and ZrO.sub.2 before and after the SOCl.sub.2 etching process. No SOCl.sub.2-derived elements remain on the surface, indicating that the process is not invasive.

TABLE-US-00005 TABLE 5 0.7% 3.4% 4.7% ZrO.sub.2 0.2 0.2 0.4 HfO.sub.2 0.2 0.7 0.2

Example 8: Cleaning Mo Film Residues

[0138] Mo films that deposited and accumulated on the inner surface of a deposition chamber are difficult to remove both mechanically and chemically. However, in the following exemplary example, it demonstrates that SOCl.sub.2 may indeed behave as etching gas for chamber cleaning with a quart tube chamber. Table 6 is the chamber cleaning conditions using SOCl.sub.2 at a temperature ranging from 200° C. to 400° C. to remove Mo residues in the quart tube chamber. FIG. 20a and FIG. 20b are the images of the quart tube chamber before and after cleaning. The results shows that the hot area of the quart tube chamber was clean, whereas the colder part outside the chamber still had deposits. FIG. 21a and FIG. 21b are the images of the hot area of the quart tube chamber before and after cleaning.

TABLE-US-00006 TABLE 6 Total Resi- re- SOCl.sub.2 dence action T.sub.cham P.sub.cham Ar FR T.sub.can P.sub.can FR PP time time (° C.) (Torr) (sccm) (C) (Torr) (sccm) (Torr) (sec) (min) 200 ~ 400 10 135 1 300 2.67 60.94 2.74 30

[0139] Although the subject matter described herein may be described in the context of illustrative implementations to process one or more computing application features/operations for a computing application having user-interactive components the subject matter is not limited to these particular embodiments. Rather, the techniques described herein can be applied to any suitable type of user-interactive component execution management methods, systems, platforms, and/or apparatus.

[0140] It will be understood that many additional changes in the details, materials, steps, and arrangement of parts, which have been herein described and illustrated in order to explain the nature of the invention, may be made by those skilled in the art within the principle and scope of the invention as expressed in the appended claims. Thus, the present invention is not intended to be limited to the specific embodiments in the examples given above and/or the attached drawings.

[0141] While embodiments of this invention have been shown and described, modifications thereof may be made by one skilled in the art without departing from the spirit or teaching of this invention. The embodiments described herein are exemplary only and not limiting. Many variations and modifications of the composition and method are possible and within the scope of the invention. Accordingly, the scope of protection is not limited to the embodiments described herein, but is only limited by the claims which follow, the scope of which shall include all equivalents of the subject matter of the claims.